Reversal of C9orf72 mutation-induced transcriptional dysregulation and pathology in cultured human neurons by allele-specific excision.

Efforts to genetically reverse C9orf72 pathology have been hampered by our incomplete understanding of the regulation of this complex locus. We generated five different genomic excisions at the C9orf72 locus in a patient-derived induced pluripotent stem cell (iPSC) line and a non-diseased wild-type (WT) line (11 total isogenic lines), and examined gene expression and pathological hallmarks of C9 frontotemporal dementia/amyotrophic lateral sclerosis in motor neurons differentiated from these lines. Comparing the excisions in these isogenic series removed the confounding effects of different genomic backgrounds and allowed us to probe the effects of specific genomic changes. A coding single nucleotide polymorphism in the patient cell line allowed us to distinguish transcripts from the normal vs. mutant allele. Using digital droplet PCR (ddPCR), we determined that transcription from the mutant allele is upregulated at least 10-fold, and that sense transcription is independently regulated from each allele. Surprisingly, excision of the WT allele increased pathologic dipeptide repeat poly-GP expression from the mutant allele. Importantly, a single allele was sufficient to supply a normal amount of protein, suggesting that the C9orf72 gene is haplo-sufficient in induced motor neurons. Excision of the mutant repeat expansion reverted all pathology (RNA abnormalities, dipeptide repeat production, and TDP-43 pathology) and improved electrophysiological function, whereas silencing sense expression did not eliminate all dipeptide repeat proteins, presumably because of the antisense expression. These data increase our understanding of C9orf72 gene regulation and inform gene therapy approaches, including antisense oligonucleotides (ASOs) and CRISPR gene editing.

The Perineuronal Net Protein Brevican Acts in Nucleus Accumbens Parvalbumin-Expressing Interneurons of Adult Mice to Regulate Excitatory Synaptic Inputs and Motivated Behaviors.

BACKGROUND: Experience-dependent functional adaptation of nucleus accumbens (NAc) circuitry underlies the development and expression of reward-motivated behaviors. Parvalbumin-expressing GABAergic (gamma-aminobutyric acidergic) interneurons (PVINs) within the NAc are required for this process. Perineuronal nets (PNNs) are extracellular matrix structures enriched around PVINs that arise during development and have been proposed to mediate brain circuit stability. However, their function in the adult NAc is largely unknown. Here, we studied the developmental emergence and adult regulation of PNNs in the NAc of male and female mice and examined the cellular and behavioral consequences of reducing the PNN component brevican in NAc PVINs. METHODS: We characterized the expression of PNN components in mouse NAc using immunofluorescence and RNA in situ hybridization. We lowered brevican in NAc PVINs of adult mice using an intersectional viral and genetic method and quantified the effects on synaptic inputs to NAc PVINs and reward-motivated learning. RESULTS: PNNs around NAc PVINs were developmentally regulated and appeared during adolescence. In the adult NAc, PVIN PNNs were also dynamically regulated by cocaine. Transcription of the gene that encodes brevican was regulated in a cell type- and isoform-specific manner in the NAc, with the membrane-tethered form of brevican being highly enriched in PVINs. Lowering brevican in NAc PVINs of adult mice decreased their excitatory inputs and enhanced both short-term novel object recognition and cocaine-induced conditioned place preference. CONCLUSIONS: Regulation of brevican in NAc PVINs of adult mice modulates their excitatory synaptic drive and sets experience thresholds for the development of motivated behaviors driven by rewarding stimuli.

An exposure-based implementation strategy to decrease clinician anxiety about implementing suicide prevention evidence-based practices: protocol for development and pilot testing (Project CALMER).

BACKGROUND: Clinicians often report that their own anxiety and low self-efficacy inhibit their use of evidence-based suicide prevention practices, including gold-standard screening and brief interventions. Exposure therapy to reduce clinician maladaptive anxiety and bolster self-efficacy use is a compelling but untested approach to improving the implementation of suicide prevention evidence-based practices (EBPs). This project brings together an interdisciplinary team to leverage decades of research on behavior change from exposure theory to design and pilot test an exposure-based implementation strategy (EBIS) to target clinician anxiety to improve suicide prevention EBP implementation. METHODS: We will develop, iteratively refine, and pilot test an EBIS paired with implementation as usual (IAU; didactic training and consultation) in preparation for a larger study of the effect of this strategy on reducing clinician anxiety, improving self-efficacy, and increasing use of the Columbia Suicide Severity Rating Scale and the Safety Planning Intervention in outpatient mental health settings. Aim 1 of this study is to use participatory design methods to develop and refine the EBIS in collaboration with a stakeholder advisory board. Aim 2 is to iteratively refine the EBIS with up to 15 clinicians in a pilot field test using rapid cycle prototyping. Aim 3 is to test the refined EBIS in a pilot implementation trial. Forty community mental health clinicians will be randomized 1:1 to receive either IAU or IAU + EBIS for 12 weeks. Our primary outcomes are EBIS acceptability and feasibility, measured through questionnaires, interviews, and recruitment and retention statistics. Secondary outcomes are the engagement of target implementation mechanisms (clinician anxiety and self-efficacy related to implementation) and preliminary effectiveness of EBIS on implementation outcomes (adoption and fidelity) assessed via mixed methods (questionnaires, chart-stimulated recall, observer-coded role plays, and interviews). DISCUSSION: Outcomes from this study will yield insight into the feasibility and utility of directly targeting clinician anxiety and self-efficacy as mechanistic processes informing the implementation of suicide prevention EBPs. Results will inform a fully powered hybrid effectiveness-implementation trial to test EBIS' effect on implementation and patient outcomes. TRIAL REGISTRATION: Clinical Trials Registration Number: NCT05172609 . Registered on 12/29/2021.

A Suicide Prevention Intervention for Emerging Adult Sexual and Gender Minority Groups: Protocol for a Pilot Hybrid Effectiveness Randomized Controlled Trial.

BACKGROUND: Suicide attempts and suicide death disproportionately affect sexual and gender minority emerging adults (age 18-24 years). However, suicide prevention strategies tailored for emerging adult sexual and gender minority (EA-SGM) groups are not widely available. The Safety Planning Intervention (SPI) has strong evidence for reducing the risk for suicide in the general population, but it is unclear how best to support EA-SGM groups in their use of a safety plan. Our intervention (Supporting Transitions to Adulthood and Reducing Suicide [STARS]) builds on content from an existing life skills mobile app for adolescent men who have sex with men (iREACH) and seeks to target core risk factors for suicide among EA-SGM groups, namely, positive affect, discrimination, and social disconnection. The mobile app is delivered to participants randomized to STARS alongside 6 peer mentoring sessions to support the use of the safety plan and other life skills from the app to ultimately reduce suicide risk. OBJECTIVE: We will pilot-test the combination of peer mentoring alongside an app-based intervention (STARS) designed to reduce suicidal ideation and behaviors. STARS will include suicide prevention content and will target positive affect, discrimination, and social support. After an in-person SPI with a clinician, STARS users can access content and activities to increase their intention to use SPI and overcome obstacles to its use. EA-SGM groups will be randomized to receive either SPI alone or STARS and will be assessed for 6 months. METHODS: Guided by the RE-AIM (reach, efficacy, adoption, implementation, and maintenance) framework, we will recruit and enroll a racially and ethnically diverse sample of 60 EA-SGM individuals reporting past-month suicidal ideation. Using a type-1 effectiveness-implementation hybrid design, participants will be randomized to receive SPI (control arm) or to receive SPI alongside STARS (intervention arm). We will follow the participants for 6 months, with evaluations at 2, 4, and 6 months. Preliminary effectiveness outcomes (suicidal ideation and behavior) and hypothesized mechanisms of change (positive affect, coping with discrimination, and social support) will serve as our primary outcomes. Secondary outcomes include key implementation indicators, including participants' willingness and adoption of SPI and STARS and staff's experiences with delivering the program. RESULTS: Study activities began in September 2021 and are ongoing. The study was approved by the institutional review board of the University of Pennsylvania (protocol number 849500). Study recruitment began on October 14, 2022. CONCLUSIONS: This project will be among the first tailored, mobile-based interventions for EA-SGM groups at risk for suicide. This project is responsive to the documented gaps for this population: approaches that address chosen family, focus on a life-course perspective, web approaches, and focus on health equity and provision of additional services relevant to sexual and gender minority youth. TRIAL REGISTRATION: ClinicalTrials.gov NCT05018143; https://classic.clinicaltrials.gov/ct2/show/NCT05018143. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/48177.

COVID-19 morbidity in lower versus higher income populations underscores the need to restore lost biodiversity of eukaryotic symbionts.

The avoidance of infectious disease by widespread use of 'systems hygiene', defined by hygiene-enhancing technology such as sewage systems, water treatment facilities, and secure food storage containers, has led to a dramatic decrease in symbiotic helminths and protists in high-income human populations. Over a half-century of research has revealed that this 'biota alteration' leads to altered immune function and a propensity for chronic inflammatory diseases, including allergic, autoimmune and neuropsychiatric disorders. A recent Ethiopian study (EClinicalMedicine 39: 101054), validating predictions made by several laboratories, found that symbiotic helminths and protists were associated with a reduced risk of severe COVID-19 (adjusted odds ratio = 0.35; p<0.0001). Thus, it is now apparent that 'biome reconstitution', defined as the artificial re-introduction of benign, symbiotic helminths or protists into the ecosystem of the human body, is important not only for alleviation of chronic immune disease, but likely also for pandemic preparedness.

Age-dependent cognitive impairment, hydrocephalus and leukocyte infiltration in transgenic mice with endothelial expression of human EPHX2.

Soluble epoxide hydrolase (sEH) is upregulated in microvascular endothelium of human brain with vascular cognitive impairment (VCI). Transgenic endothelial expression of human sEH in mice (Tie2hsEH) induces endothelial dysfunction (ED), a pathogenetic mechanism of VCI. We sought to determine if endothelial upregulation of sEH is sufficient to cause cognitive impairment, and if cognitive impairment due to chronic hypoperfusion induced by unilateral common carotid artery occlusion (CCAO) is exacerbated in Tie2hsEH mice. Behavioral performance was assessed by the open field, rotarod, novel object, Morris water maze and fear conditioning tests. Cerebral blood flow and brain morphology were evaluated by MRI, and inflammatory changes investigated using immunohistochemistry and flow cytometry. We demonstrate that transgenic endothelial expression of sEH is sufficient to induce cognitive impairment, associated with leukocyte infiltration, brain atrophy and accelerated, age-dependent ventriculomegaly, identifying ED and sEH upregulation as potential underlying mechanisms and therapeutic targets for VCI.

The safety of pediatric use of paracetamol (acetaminophen): a narrative review of direct and indirect evidence.

Paracetamol (acetaminophen) use during pregnancy and early childhood was accepted as safe in the 1970s, but is now a subject of considerable concern. Careful analysis shows that initial acceptance of the drug was based on the false assumption that drug interactions in babies and adults are the same, and on a complete absence of knowledge regarding the impact of the drug on brain development. At least fourteen epidemiological studies now indicate that prenatal exposure to paracetamol is associated with neurodevelopmental problems. Based on these studies, it can be concluded that prenatal exposure to paracetamol causes statistically significant risks of developmental delays, attention deficit hyperactivity disorder, and a subtype of autism spectrum disorder (ASD) associated with hyperkinetic behavior. In contrast, data regarding postnatal exposure to paracetamol are limited, and several factors impede a classic multivariate analysis of epidemiologic data to resolve the issue. However, circumstantial evidence regarding postnatal exposure to the drug is abundant, and includes at least three otherwise unexplained temporal relationships, data from laboratory animal studies, several miscellaneous and otherwise unexplained correlations, and a lack of alternative suspects that fit the evidence-derived profile. Based on this evidence, it can be concluded without any reasonable doubt that oxidative stress puts some babies and children at risk of paracetamol-induced neurodevelopmental injury, and that postnatal exposure to paracetamol in those susceptible babies and children is responsible for many if not most cases of ASD.

Effects of Chronic Secondhand Smoke (SHS) Exposure on Cognitive Performance and Metabolic Pathways in the Hippocampus of Wild-Type and Human Tau Mice.

BACKGROUND: Exposure to secondhand smoke (SHS) is a risk factor for developing sporadic forms of sporadic dementia. A human tau (htau) mouse model is available that exhibits age-dependent tau dysregulation, neurofibrillary tangles, neuronal loss, neuroinflammation, and oxidative stress starting at an early age (3-4 months) and in which tau dysregulation and neuronal loss correlate with synaptic dysfunction and cognitive decline. OBJECTIVE: The goal of this study was to assess the effects of chronic SHS exposure (10 months' exposure to ∼30 mg/m3) on behavioral and cognitive function, metabolism, and neuropathology in mice. METHODS: Wild-type (WT) and htau female and male mice were exposed to SHS (90% side stream, 10% main stream) using the SCIREQ® inExpose™ system or air control for 168 min per day, for 312 d, 7 d per week. The exposures continued during the days of behavioral and cognitive testing. In addition to behavioral and cognitive performance and neuropathology, the lungs of mice were examined for pathology and alterations in gene expression. RESULTS: Mice exposed to chronic SHS exposure showed the following genotype-dependent responses: a) lower body weights in WT, but not htau, mice; b) less spontaneous alternation in WT, but not htau, mice in the Y maze; c) faster swim speeds of WT, but not htau, mice in the water maze; d) lower activity levels of WT and htau mice in the open field; e) lower expression of brain PHF1, TTCM1, IGF1ß, and HSP90 protein levels in WT male, but not female, mice; and f) more profound effects on hippocampal metabolic pathways in WT male than female mice and more profound effects in WT than htau mice. DISCUSSION: The brain of WT mice, in particular WT male mice, might be especially susceptible to the effects of chronic SHS exposure. In WT males, independent pathways involving ascorbate, flavin adenine dinucleotide, or palmitoleic acid might contribute to the hippocampal injury following chronic SHS exposure. https://doi.org/10.1289/EHP8428.

Novel Antimicrobial Peptides Formulated in Chitosan Matrices are Effective Against Biofilms of Multidrug-Resistant Wound Pathogens.

INTRODUCTION: Infection frequently complicates the treatment of combat-related wounds, impairs healing, and leads to worse outcomes. To better manage wound infections, antimicrobial therapies that are effective against biofilm and designed for direct wound application are needed. The primary objective of this work was to evaluate a chitosan matrix for delivery of two engineered antimicrobial peptides, (ASP)-1 and ASP-2, to treat biofilm-associated bacteria. A secondary objective was to determine whether replacing the levorotatory (L) form amino acids in ASP-2 with dextrorotatory (D) form amino acids would impact peptide activity. MATERIALS AND METHODS: Chitosan gels loaded with antimicrobial peptides were evaluated for peptide release over 7 days and tested for efficacy against biofilms grown both in vitro on polymer mesh and ex vivo on porcine skin. RESULTS: When delivered via chitosan, 70% to 80% of peptides were released over 7 days. Gels eradicated biofilms of gram-positive and gram-negative, drug-resistant bacteria in vitro and ex vivo. Under the conditions tested, no meaningful differences in peptide activity between the L and D forms of ASP-2 were detected. CONCLUSIONS: Chitosan serves as an effective delivery platform for ASP-1 and ASP-2 to treat biofilm-embedded bacteria and warrants further development as a topical treatment.

Apolipoprotein E4 mediates insulin resistance-associated cerebrovascular dysfunction and the post-prandial response.

Metabolic dysfunction, commonly a result of diets high in saturated fats and sugar, is associated with impaired cognitive function and an increased risk of age-related cognitive decline (ACD) and Alzheimer's disease (AD). Compared to the E3 isoform of apolipoprotein (apoE), the E4 isoform is a major genetic risk factor for ACD, AD, and for developing cognitive impairments following various environmental challenges, including dietary challenges such as a high-fat diet (HFD). Both insulin resistance (IR) and E4 are associated with metabolic and vascular impairments. Deficits in cerebral metabolism and cerebrovascular function have been proposed as initiating events leading to these impairments. In the current study, we employed a model of human apoE targeted replacement mice and HFD-induced obesity to study the potential link between E4 and IR, at rest and following a postprandial challenge. HFD-induced IR was associated with impaired cognition, reduced cerebral blood volume and decreased glucose uptake. These effects were more profound in E4 than E3 mice. Furthermore, the cognitive, metabolic and cerebrovascular responses to an exogenous glucose load showed an apoE isoform-dependent response, with E4, but not E3 mice, acutely benefiting from a spike in blood glucose.

Dlx1/2 and Otp coordinate the production of hypothalamic GHRH- and AgRP-neurons.

Despite critical roles of the hypothalamic arcuate neurons in controlling the growth and energy homeostasis, the gene regulatory network directing their development remains unclear. Here we report that the transcription factors Dlx1/2 and Otp coordinate the balanced generation of the two functionally related neurons in the hypothalamic arcuate nucleus, GHRH-neurons promoting the growth and AgRP-neurons controlling the feeding and energy expenditure. Dlx1/2-deficient mice show a loss-of-GHRH-neurons and an increase of AgRP-neurons, and consistently develop dwarfism and consume less energy. These results indicate that Dlx1/2 are crucial for specifying the GHRH-neuronal identity and, simultaneously, for suppressing AgRP-neuronal fate. We further show that Otp is required for the generation of AgRP-neurons and that Dlx1/2 repress the expression of Otp by directly binding the Otp gene. Together, our study demonstrates that the identity of GHRH- and AgRP-neurons is synchronously specified and segregated by the Dlx1/2-Otp gene regulatory axis.

A Novel Peptide-Based Antimicrobial Wound Treatment is Effective Against Biofilms of Multi-Drug Resistant Wound Pathogens.

Wound infections are a common complication of combat-related injuries that significantly increase morbidity and mortality. Multi-drug resistant (MDR) organisms and their associated biofilms play a significant role in the pathogenicity and chronicity of wound infections. A critical barrier to progress in the treatment of traumatic wounds is the need for broad spectrum antimicrobials that are effective against biofilms and compatible with topical delivery. In this study, we present the in vitro efficacy of two de novo designed cationic, antimicrobial peptides and related topical formulations against single species and polymicrobial biofilms of MDR bacteria. Minimum biofilm eradication concentrations for peptides ranged from 0.7 µM for Staphylococcus aureus to 13.2 µM for Pseudomonas aeruginosa. Varying pH did not adversely impact peptide activity, however, in the presence of albumin, minimum biofilm eradication concentrations generally increased. When formulated into gels or dressings, both peptides eradicated mono- and polymicrobial biofilms of MDR pathogens. The biocompatibility index (BI) was found to be greater than one for both ASP-1 and ASP-2, with a slightly greater (more favorable) BI for ASP-2. The BIs for both peptides were greater than BIs previously reported for commonly used topical antimicrobial agents. The antimicrobial peptides and related formulations presented provide a promising platform for treatment of wound biofilms to improve outcomes for those injured in combat.

Microbial evaluation of Limnophila rugosa Roth. (Merr) leaf.

BACKGROUND: Limphonia rugosa Roth. (Merr.), family-Scrophulariaceae is considered as a botanical source of classical Ayurvedic drug Bhringaraja by the traditional practitioners of Odisha and is being used for the management of various disorders. AIM: To study the antimicrobial activity of leaf of L. rugosa. MATERIALS AND METHODS: Methanol extract of L. rugosa leaf (LRLM) has been studied, at various (5, 25, 50, 100, 250 µg/ml) dilutions, against medically important human pathogenic bacteria (two Gram-positive Staphylococcus aureus, Streptococcus pyogenes and two Gram-negative-Escherichia coli, Pseudomonas aeruginosa) and two fungal strains (Aspergillus niger, A. clavatus, Candida albicans) by using the agar disc diffusion method. A zone of inhibition of extract was compared with that of different standards such as ampicillin, ciprofloxacin, norfloxacin and chloramphenicol for antibacterial activity and nystatin and griseofulvin for antifungal activity. RESULTS: The antibacterial and antifungal activities of the LRLM increased linear with the increase in concentration of extracts. When compared with standard drugs, the results revealed that, for bacterial activity S. pyogenes and S. aureus were more sensitive and in fungal activity C. albicans was more inhibited. The range of growth inhibition zone for all the sensitive bacteria was 11-20 mm and 13-19 mm for fungal strains. CONCLUSION: Methanolic extract of L. rugosa leaf is having antibacterial and antifungal activities.

Detection and analysis of Staphylococcus aureus isolates found in ambulances in the Chicago metropolitan area.

BACKGROUND: Given the frequency with which many different strains of Staphylococcus aureus are found in various prehospital settings, this study sought to characterize S aureus isolates taken from one such environment. The objectives were to determine the frequency of S aureus in front-line, advanced life support (ALS) ambulances throughout the Chicago metropolitan area, and to generate antibiograms (antibiotic resistance profiles) for each S aureus isolate using 8 clinically relevant antibiotics. METHODS: Samples were obtained from 26 sites in 71 ambulances from 34 different Chicago-area municipalities. Selected colonies that demonstrated a growth pattern consistent with that of S aureus were subjected to a latex agglutination test specific for S aureus. Antibiograms and genetic analyses were performed on all latex agglutination test-positive isolates. RESULTS: At least one S aureus isolate was found in approximately 69% of all ambulances in the study. Of all isolates detected, 77% showed resistance to at least one antibiotic, and 34% displayed resistance to 2 or more antibiotics. Some level of oxacillin resistance was found in 21% of isolates; however, only slightly more than half of these oxacillin-resistant isolates were found to carry the methicillin-resistant S aureus-specific SCCmec cassette. Some 12% of all isolates were ultimately determined to be methicillin-resistant S aureus, whereas the remaining 88% were methicillin-sensitive S aureus with varying antibiograms. CONCLUSIONS: Antibiotic resistance appears to be prevalent in S aureus isolates detected in Chicago area ALS ambulances. Given the ease with which S aureus can survive on inanimate surfaces and exchange antibiotic resistance elements, a conscientious approach to the application of existing cleaning techniques, especially in key ambulance sites, is needed. Future work will include further characterizing isolates using multiple techniques, as well as follow-up studies with interested municipalities.